The radio module efficiency is a key figure for radio products as it relates to: i) the electricity bills (OPEX—operating cost); ii) the volume/size of the radio module (the less efficient operation, the more power to dissipate, the bigger is the required size of the heat sink); iii) the level of energy waste (Green operation classification of products). Hence, maximizing the efficiency is one of the key targets for next generation radio modules. Most of today's radio modules adopt the usage of high efficiency Doherty amplifiers. For future radios, it is required to deliver an optimized Doherty operation using a smart digital Doherty architecture.
Radio module's linearity is a key requirement for radio products in order to fulfil the spectrum emission requirements set by the respective standards (e.g. 3GPP) and authorities and in order to maintain low bit error rate which impact directly the system capacity. For certain applications, radio module linearity is also a key requirements for high capacity systems based on antenna signal processing (i.e., diversity/beamforming). It is important to deliver high radiated output power without increasing challenges on linearization techniques, without increasing the HW/SW complexity of the radio module.